Salim Ok

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTHydrogen-Bonded Polymer Capsules Formed by Layer-by-Layer Self-AssemblyVeronika Kozlovskaya, Salim Ok, Alioscka Sousa, Matthew Libera, and Svetlana A. SukhishviliView Author Information Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030 Cite this: Macromolecules 2003, 36, 23, 8590–8592Publication Date (Web):October 25, 2003Publication History Received26 July 2003Revised7 October 2003Published online25 October 2003Published inissue 1 November 2003https://pubs.acs.org/doi/10.1021/ma035084lhttps://doi.org/10.1021/ma035084lrapid-communicationACS PublicationsCopyright © 2003 American Chemical SocietyRequest reuse permissionsArticle Views2084Altmetric-Citations154LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Deposition,Layers,Polymer particles,Polymers,Thin films Get e-Alerts

In crude oil production and processing, asphaltene aggregation followed by precipitation is a major problem for the oil industry as it causes deactivation of catalysts, blocking pipelines, and deposition on the internal surface of the reservoirs, etc. Asphaltenes, a complex mixture of a broad distribution of molecules, consisting of aromatic cores bonded to aliphatics and porphyrin type molecules with heavy metals, are defined based on solubility. Molecular complexity along with varying molecular weight distribution makes asphaltenes a difficult scientific problem to characterize. Over several decades, many researchers have contributed to characterization, analysis, and determination of structural properties of asphaltenes by various analytical techniques. Nuclear magnetic resonance (NMR) spectroscopy and relaxometry are widely applied for characterizing the chemical structures of asphaltenes, interactions between asphaltenes and maltenes, and dynamical behaviors of asphaltenes in bulk and in confined states. The goal of the current review article is to give an insight into various aspects of asphaltene analysis by NMR spectroscopy and relaxometry. Following a short introduction on asphaltenes and theory of NMR technique, recent contributions on asphaltenes by NMR techniques are summarized and presented. Lessons learned and suggestions on possible future work conclude the present review article.

ADVERTISEMENT RETURN TO ISSUECommunication to the...Communication to the EditorNEXTConfinement Effects on Chain Dynamics and Local Chain Order in Entangled Polymer MeltsSalim Ok, Martin Steinhart, Anca Şerbescu†, Cornelius Franz, Fabián Vaca Chávez‡, and Kay Saalwächter*View Author Information Institut für Chemie, Universität Osnabrück, Barbarastr. 7, D-46069 Osnabrück, Germany Institut für Makromolekulare Chemie, Universität Freiburg, Stefan-Meier-Str. 31, D-79104 Freiburg, Germany Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, D-06120 Halle, Germany*To whom correspondence should be addressed. E-mail: [email protected]†Now at: Dow Europe GmbH, Horgen, Switzerland‡Now at: Universidade de Lisboa, Lisbon, PortugalCite this: Macromolecules 2010, 43, 10, 4429–4434Publication Date (Web):April 23, 2010Publication History Received10 February 2010Revised13 April 2010Published online23 April 2010Published inissue 25 May 2010https://doi.org/10.1021/ma1003248Copyright © 2010 American Chemical SocietyRIGHTS & PERMISSIONSACS AuthorChoiceArticle Views2741Altmetric-Citations56LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-AlertsSUBJECTS:Magnetic properties,Membranes,Polymers,Quantum confinement,Silicones Get e-Alerts

Adulteration of olive oil using unhealthy substitutes is considered a threat for public health. Low-field (LF) proton (1H) nuclear magnetic resonance (NMR) relaxometry and ultra-violet (UV) visible spectroscopy are used to detect adulteration of olive oil. Three different olive oil with different oleoyl acyl contents were mixed with almond, castor, corn, and sesame oils with three volumetric ratios, respectively. In addition, Arbequina olive oil was mixed with canola, flax, grape seed, peanut, soybean, and sunflower seed oils with three volumetric ratios. Transverse magnetization relaxation time (T2) curves were fitted with bi-exponential decaying functions. T2 times of each mixture of olive oils and castor oils, and olive oils and corn oils changed systematically as a function of volumetric ratio. To detect the adulteration in the mixtures with almond and sesame oils, both LF 1H NMR relaxometry and UV-Vis spectroscopy were needed, where UV-Vis-spectroscopy detected the adulteration qualitatively. In the mixtures of Arbequina olive oil and flax, peanut, soybean, and sunflower seed oils, both T21 and T22 values became longer systematically as the content of the olive oil was decreased. The unique UV-Vis maximum absorbance of flax oil at 320.0 nm shows the adulteration of olive oil qualitatively.